My 1949 house still has mostly Type A (2 “pin,” one wider than other) outlets. I wrote “mostly” because at some point a previous owner had the half-dozen outlets in the living room (and a few other spots) replaced with Type B (3 pin). They are apparently not, however, grounded (or “properly” grounded) according to the guy that inspected the house.
Should I care? In 5 years it has not been a great inconvenience.
It doesn’t meet code and could show up in an inspection if you were selling the house. Many localities will not allow the sale of a house until the violations are corrected. It’s not unsafe except if you expect the ground protection to be there.
Dennis
IIRC existing installations of NEMA 1 receptacles are grandfathered in (if built prior to 1974,) to the point where it’s still OK to buy and install new 2-blade receptacles if and only if they are replacing a NEMA 1 receptacle. IIRC it would be a violation to install a grounding NEMA 5 receptacle in its place if no safety ground wire is present.
I had a house in Canada built about 1962 and we replaced all the 2-pin with 3-pin grounded. My father-in-law was quite adventurous, he helped me and showed me how to change them without turning of the power (hint - carefully! I only blew up 1 outlet) However in this case, the house was wired with grounded wires, but the ground was attached to the electrical box; so it was a matter of connecting the ground to the outlet ground or running a wire from the box ground screw to the outlet.
I’m guessing since you did not mention it that your house does not have that ground wire in the cabling to each outlet box?
Old 2 prong outlets as old as yours can easily fail and cause problems. I’d recommend replacing them just because of their age.
You should also have an electrician (or at least someone with a knowledge of wiring) take a look at your wires. A house built in 1949 could have anything from knob and tube to romex in it (technically romex is a brand name, like kleenex, and the wire is more properly called nm cable for “non-metallic”). Knob and tube and the old paper insulation would have been old-fashioned and not as likely to be used, but you never know. Knob and tube is technically ok to keep using as long as you have it inspected periodically and keep in maintained, but personally I would remove it and upgrade it to modern wiring. You might also have an earlier romex-like type of wiring that has insulation made out of a rubber and cloth type of material. That insulation degrades over time, and if you have it, you would be wise to replace it before it fails.
If you don’t have the ground connected and you connect a 3 prong device to the outlet, the case of the device can easily end up at 120 volts and create a shock hazard. I have seen this several times with desktop computer cases but it is by no means restricted to computers. Anything that uses a 3 prong plug and has a metal case could be potentially deadly. It’s a fairly serious safety hazard.
The fact that it hasn’t caused you any issues in 5 years doesn’t say much. You might continue to use it for another 20 years and not have an issue, or it could burn your house down tomorrow. Inspect it to see what you have going on underneath, and go from there.
Is upgrading the wiring in a house a big expensive (over $3,000) job. It’s a 1300 sq ft house ( plus a full, mostly finished basement)
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Is it drywall or lathe-and-plaster?
My first thought is that the majority of the fixes can be done by ripping out the ceiling in the basement and drilling up from there to run wiring. But then there are complications for things like kitchen counter wiring, and whether the lights and plugs share a wiring run… and then what? you’d have to strip huge chunks of the wall and ceiling if so. And can you rewire just the plugs and not the lighting? I guess that’s a code question - can you do part of the wiring or do you have to go whole hog?
I think it would save a lot of the cost if you could do the wall stripping and re-plastering yourself and let an electrician do just the wiring. How’s your drywall skills?
but then, you’d probably replace the panel also, wouldn’t you? Or is that still serviceable? I seem to recall that back in the 1940’s some power panels were screw-in fuse types.
An improvement that’s much simpler than providing ground to each outlet would be to replace each outlet with a GFCI outlet. It’s not as good as having ground, but it’s much safer than plugging a 3-prong plug into an ungrounded outlet.
I would say probably well over $3000. We had our ~1000 sq. ft. house (all one floor) done almost 6 years ago, and it was considerably more than that. (I’m not being coy, I honestly don’t remember now.)
Actually, a 3-pin receptacle would have been already grounded – since the 1970s, NEC has required that receptacles be built so that the screws holding them into a metal box also grounds them. Using a tester on them will show a valid ground connection. (But it’s still much better to actually wire them to the ground wire.)
A whole house is a big, expensive job. But you can keep the expense down if you can do parts of the job yourself. Also, you can spread the expense out, by doing part at a time, as you have funds. But any circuit you work on, you have to bring the whole circuit up to code.
So if you have 2 receptacles on different bedroom walls that are both on the same circuit, you shouldn’t change one of them to a 3-wire grounded outlet and leave the other an old 2-wire ungrounded. (But you can get around this by splitting the circuit – if one wall is hard to get to, leave that old outlet on the old circuit, and run a new circuit with new 3-wire outlets on the other wall.) So you kinda end up rewiring a circuit at a a time, replacing as you go (and usually, adding more receptacles than they had in 1940).
If you do this, start with the kitchen & bathroom. Those are the most heavily used *electrically) and the most dangerous (electricity + water). Unfortunately, they are often the most complicated to do. Consider just leaving what is there, and installing a completely new set of circuits & outlets. When those are done & working, cut off the old ones & switch to the new circuits. You can abandon the old wiring in the walls, or pull it out & recycycle the copper, as you wish.
This assumes that the box is metal, and if it is, that the box itself is properly grounded. Either condition may be false, and a three-prong receptacle installed by a weekend warrior handyman in such a case will not be safe.
A GFCI can be used in cases where it would be impractical to add proper grounding.
A half dozen outlets in the living room of a 1300sqft house built in '49 is about twice the number of receptacles I’d expect to see around here. I’d start with the service and panel if it hasn’t been done recently anyways. It’s where all your grounding originates and you’ll need room for expansion.
sounds like your 2-pin were already upgraded under the grandfathered in clause. Polarized (one wider pin) receptacles were not commonly used in 1949.
I’m going to guess that non-metal boxes (PVC?) were probably a more recent invention. My point was that even in 1962 - at least in Canada - the wiring was 3-wire and included a bare ground wire in the full wrapped cabling, it was attached to the (metal) outlet box because there was no ground/plug connection at the time.
Still - would you have to replace the whole panel too? That is a job for a real electrician and would probably cost you bigly, and needs to be done for all the wiring at once.
My understanding is that in many places, wiring can be done by the homeowner provided an electrician approves of their work (and a building inspector probably ahs to look at it too, and you need a permit to touch anything electrical…)
I heard about one homeowner in Canada (on the news) who wanted to upgrade his plumbing, and was told that if he opened the wall he would have to replace everything in the wall including electrical, and he would have to replace ALL plumbing, the grandfather rule expired once you started to work on things. YMMV.
If you’re drilling in from underneath and fishing the wire through the walls from the basement - does code allow for free-hanging wire or do you have to open up the wall and staple the wire to a stud? I know from a friend who built his own home, that the wiring standard was to staple to the stud and then have an arc of about 6 inches of slack leading into the outlet box, in case in future more slack was needed in the box.
(Current code here is 12 feet between outlets along the wall, not counting doors and windows. This is because most lamps and other appliances have a 6 foot cord, so should reach an outlet from anywhere along the wall. Really old houses, especially retro-fitted 1900 houses, tended to have one outlet per room if you were lucky. )
An electrician gave me an estimate of $20,000 for rewiring our 1800 sq. ft. 1942 vintage house. And we already had a modern circuit breaker box, 200 A service and a number of 3 wire grounded sockets, including the entire kitchen and where my and my wife’s computers were plugged in. But the rest of the house had only two-pronged non-polarized sockets.
I’ve got five bucks that says that electrician just overbid because he doesn’t want to do that kind of work. Not that it’s cheap, but I’m sure a house like that could be rewired for a lot less than 20 grand. Especially if you’re willing to consider slightly ugly solutions like surface-mount conduit.
Rewiring an occupied house, especially one with laminate floors and lots of furniture is the kind of job electricians have nightmares (and tell ‘funny’ stories on forums) about.
As a couple others have mentioned, if there’s no ground wire, you can replace a two-prong receptacle with a three-prong receptacle as long as it is GFCI protected. It’s not as “good” as running a ground wire to each receptacle, IMO, but it’s legal.
There are three ways to do this:
Replace each two-prong receptacle with a (three prong) GFCI receptacle.
Locate the most “upstream” receptacle in a branch circuit. Replace that receptacle with a GFCI receptacle. Then replace all the “downstream” receptacles with standard, three-prong receptacles.
Replace the circuit breaker for the branch circuit with a GFCI circuit breaker. Then replace all the receptacles in the circuit with standard, three-prong receptacles.
When doing any of the above, the three-prong receptacles must have stickers on them that say “GFCI Protected” and “No Equipment Ground.”
That’s funny. Had almost the exact same thread 4 months ago.
55 year old home, all 2 prong outlets replaced with ungrounded 3 prong-remedy?